To overcome the overcoming of agglomeration and reclamation of nanoparticulate materials, it is imperative to synthesize nanosized materials with other morphologies. Fe3O4nanotubes were synthesized by using anodized aluminum oxide as template under microwave assistance by tuning the deposition mechanism in this work. The obtained nanotubes were characterized by the means of XRD and SEM. Its magnetic property was also investigated. Results show that tubes are of the spinel structure, a layer of about 30 nm Fe3O4was deposited attaching to the AAO wall, and the nanotubes possess good magnetic performance.

A novel watershed algorithm using mountain areas simulation method to segment the field emission images was proposed for the first time. In the algorithm, field emission sites in the images are compared to many mountaintops. The small fluctuations in the mountains are first erased by filling method. And then the traditional watershed transform is applied to get the mountain areas roughly. At last the parameters of the relative height needed for a mountaintop are used to segment the field emission sites by a series image process of dilation and comparation. This segmentation method is very easy to be accomplished in MATLAB and have high efficiency. Results show that the improved watershed algorithm is feasible in analyzing field emission properties and some other applications.